Mobile communication devices (such as a PDA, smart phone, mobile phone etc.) are in use throughout everyday life. There is a significant amount of highly confidential and sensitive information stored on these devices, especially in the case of corporate-issued devices. Typically, these devices use a local password login scheme in order to grant access to the device and its content. The user must input his/her password prior to any action being taken with the device (with the possible exception of emergency calls). This system requires the user to type in an alphanumeric password using the keypad. However, having to manually type in a password can be inconvenient and/or difficult to do especially in one-handed use situations such as, for example, while driving or doing other tasks where one hand may be busy, such as walking while carrying a briefcase. In addition, password entry systems are typically only configured to work with a single device and for a single person i.e. if a user wishes to share access with another user, the user must share his/her password. Such sharing of passwords can lead to potential security breaches, especially if a user's password gets into the hands of an unauthorized individual.
Use of other biometric indicators such as fingerprints, voice authentication or the like have been proposed for use in limiting access/unauthorized use of a device. However, in order to be accurate and efficient, these biometric indicators typically require significant processing power and memory, both of which may be limited, especially on a mobile device. Further, some existing systems appear to generally focus on limiting access to the communications network rather than on limiting access to the mobile device itself.
There remains a need for an efficient and relatively simple but robust system and method for unlocking a device, and in particular, a mobile communications device.